I just upgraded my Maverick to Natty 3 days ago. It's fun and good. I try to be familiar with Unity, but the Natty constantly freezes suddenly. I try another alternative, I use Ubuntu Classic instead of Unity, and at the end my computer continues freezing suddenly and it made me really angry, I can't do anything except of force my computer to shut down through the power button. My laptop is Compaq CQ20 windows & 32bit
Add this to your repositories.
or in the terminal:
or Open the Software Sources menu by going to Applications->Ubuntu Software Center, then selecting Edit->Software Sources. Choose the Other Software tab and click Add.
see if it helps.
I have an HP MINI 210 and it freezes like yours, my issue? the wireless card!
the solution: blacklisting the following drivers:
(this should be appended to the file /etc/modprobe.d/blacklist.conf)
then restart and it should be working if this is your issue!
if this doesn't work, don't forget to remove those lines from the file.
Besides Uri answer try this too: enable proposed updates in Software Sources, and update your system to 2.6.38-9 kernel. Maybe this helps.